How do international transfers work?

Transfers between clubs in different countries must include Fifa's international transfer certificate (CIT). It is this document that the French football authorities were waiting to receive.

Neymar's move to France has been troubled since the release clause in his contract was triggered.

Spain's La Liga believes PSG are violating Uefa's financial fair play (FFP) rules and Barcelona previously said they would report the French club to European football's governing body, Uefa, for a FFP breach.